Family-friendly chicken fajitas inspired this easy dinner on a baking sheet. We add the ingredients in stages to ensure each cooks perfectly. First, we cook earthy poblano chilies and onions until tender. Then sweet-tart tomatoes join the mix, followed by boneless chicken parts, which need only a quick-roast to cook through. Tangy tomatillos can be substituted for tomatoes, bringing more bright acidity. For a low-effort taco night, serve with warm tortillas and an array of condiments.